# Nymchat Knowledge Base

Everything the app does, why it does it that way, and what it costs you in privacy to use each part. Written against the source code, not with fluff marketing.

[▶ Thirty seconds of Nymchat. Every screen is the real app.](https://nymchat.app/media/nymchat-promo.mp4)

## What is Nymchat

Nymchat — also written NYM, for Nostr Ynstant Messenger — is a chat client built on the [Nostr](https://github.com/nostr-protocol/nostr) protocol. There is no account to create and no server that owns your messages. You pick a nym, a keypair is generated on your device, and you start talking.

It runs in three places, from one codebase per platform and one network:

- a **Progressive Web App** in any modern browser, installable to a home screen or dock;
- a native **Android** app;
- a native **iOS** app.

All three speak the same protocol to the same relays, so who you talk to never depends on which one they are running. See [Apps and platforms](https://nymchat.app/docs/apps/) for what differs between them.

## How to read this

The sidebar is the full table of contents, and it is the same on every page. The box in the top bar filters it — including the headings inside pages you are not currently on — so it works as a search across the whole knowledge base. Press `/` anywhere to jump into it.

If you have never used Nymchat, read [Getting started](https://nymchat.app/docs/getting-started/) first and follow the sidebar in order. If you are looking for one specific thing, filter for it.

- [Getting started](https://nymchat.app/docs/getting-started/): Open the app, pick a nym, join a channel, say something.
- [How Nymchat compares](https://nymchat.app/docs/comparison/): Against Signal, Briar, Bitchat, SimpleX, Armada and nine more, feature by feature.
- [Identity and login](https://nymchat.app/docs/identity/): Ephemeral nyms, Nostr accounts, and what each one leaks.
- [Bluetooth mesh](https://nymchat.app/docs/mesh/): Messaging with no internet, no cell service and no infrastructure.
- [Command reference](https://nymchat.app/docs/commands/): Every slash command and every Nymbot command, in one place.
- [Press kit and brand](https://nymchat.app/brand/): Boilerplate, fast facts and screenshots for the press, and what you may do with the wordmark.

## The short version

If you read nothing else:

- **Public channels are public.** Anything you send to a channel is an unencrypted event on public relays. Treat it as a broadcast.
- **Private messages and group chats are end-to-end encrypted.** Relays carry them as gift wraps addressed to one-time keys and cannot read them or tell who is in a conversation.
- **An ephemeral nym is not an anonymity system.** It hides your identity from other users, not your IP address from a relay operator.
- **Your keys live on your device.** Nobody can recover them for you. If you want a persistent identity, back up its private key yourself.

> **Note**
>
> This knowledge base describes what the app does. It is not legal advice, and it is not a promise about how any particular relay operator behaves. For the terms that govern using the hosted service, see the [Terms of Service](https://nymchat.app/terms/) and the [Privacy Policy](https://nymchat.app/privacy/).